Air bag tubing size

[luvrbus]

Coach Services , Gary you still making and selling the kits ?

[CoachServices LHC]

Yes Clifford:  Have all the old parts & skill to make them but I am retired/tired.

[kyle4501]

Mine has 3 height valves as original equipment. I figure GM had a good engineering reason why they didn't use 4.

However, with 4 corner control & an axle hook, you wouldn't need a jack to change a tire. 

[luvrbus]

I have had both still have a 3 point leveling system to me  the 4 corner( Bi Axis) is a far superior system

[kyle4501]

I guess I'm too dense to see it for myself, so could you please explain how the 4 is a better system?

I can't seem to get past the fact that a 3 leg stool doesn't rock, but a 4 leg stool, if not on a perfect floor, will leave one hanging. . . .

[luvrbus]

I had a HWH 4 point hydraulic system on the Eagle solid as a rock I now have a 3 point RVS hydraulic system on the motor home there is always a little movement in the front with the single jack mounted on the front, the rear is solid with the 2 jacks that is what I go by

[uncle ned]

Kyle   drive you little convertible down a crooked road.  then ride a three wheel motorcycle down the same road.

that is the difference in the stability of levelers also.

uncle ned

[kyle4501]

Air bags will be bouncy, regardless of how many valves you have on them. 

Hydraulic cylinders will be rock solid, since hydraulic fluid doesn't compress.
I would think the bounce from a 3 hyd cyl setup is the frame flexing/ twisting. I'm guessing with air bags, it would be difficult to distinguish the difference in vehicle flex & air bag bounce.

I do agree that a 4 point system with hydraulic cylinders can have less bounce or movement. However, with air bags, it won't matter how many valves one uses - air still compresses.

Regarding frame twist with air bags, if it makes that big a difference, maybe you should get a better chassis to start with. 

As for the drive on a crooked road - I do remember some from the vehicle dynamics classes & what happens if a wheel lifts off the road.

About a 3 wheeled motorcycle - nope, ain't gonna ride one of those. I can barely control a car with 4 wheels, I don't stand a chance with 3 ! 

If I were doing a hyd leveling system, it would have 4 cylinders, 2 height valves at the rear & 1 at the front. Once leveled, the front cylinders would then be isolated from each other. Seems like a good idea to me anyways. . . . .

[Oonrahnjay]

      I'm looking at doing one of these systems, but so far it's all theory and I've only been listening to what people say.  Thanks for the info, Gary -- I'm not sure I know enough to think outside the box but you're certainly made my box for thinking bigger.
      Considering this discussion, maybe it's that three point is "idiot proof" (but doesn't support the bus well) and four point requires care to correctly get the frame supported at four points but once it's set and is properly lifting the four points in correct balance, the support is more solid?

[sparkplug188]

Has anybody thought of using these:

8 Ton Long Ram Air/Hydraulic Jack
http://www.harborfreight.com/8-ton-long-ram-air-hydraulic-jack-94562.html

16,000lbs capacity
air operated, manual backup
17.5" stroke
35.7lbs

It would need a large retracting spring, like this:

National Hardware 7688 Garage Door Extension Spring with Safety Cable
http://www.amazon.com/National-Hardware-Extension-25-Inch-110-Pound/dp/B000B4N0SO/ref=sr_1_1?ie=UTF8&qid=1415974854&sr=8-1&keywords=garage+door+spring

Both mounting points on the jack are pivots, so they can't be mounted like "normal" RV leveling jacks (straight up and down, without bracing).  They need to mount similar to backhoe outriggers- see the first picture below.  On a bus, I would mount the ram nearly vertical and mount the outrigger pivot near the differential- see second picture below.





I do not know how the professional leveling systems deal with hydraulic "bleed down".  There must be some sort of locking system that I am not seeing.  I am not sure how to lock outriggers in place.  There is probably a simple way to do it that I am not thinking of.

It wouldn't be a fully automatic leveling system, but it would be an effortless way to level a bus without spending $4000+ on a leveling system.

[luvrbus]

The HWH mounted on the Eagle were on a angle like 12 inches over center when extended lol the 4000 bucks is for the Big Foot leveling system, Jesse the HWH 64,000 lbs I had installed cost a little more lol almost double.

You being a Eagle owner I am sure you know this but the 4 corner air leveling system (not 3) was a option on the motor home chassis from Eagle, I have the schematics and parts list in my model 15 manual if you want a set

[sparkplug188]

  NOPE! 100X nope! I would live life tilted a few degrees sideways and save the $8000 for a rebuilt engine.  My experiment will cost no more than $500 in materials.  That is about as much as I will pay for a level bus.  

Edit: I have actually considered adding air bags to my Eagle just for leveling.  The air bags and hookups aren't too expensive... and in 10 to 20 years I will need them when the Torsilastic suspension runs out of adjustment rod.  The hardest part about putting air bags on an Eagle is designing strong enough mounts.  There are some guides on Eagles International that I have been looking at.

Edit 2: Yes, please!  I am very curious of how Eagle mounted the air bags from the factory.  Sorry about the last schematic (fuel line diagram)-- send it however is easiest for you.  Facebook, Google+, email, post office-- you name it.

[luvrbus]

If you go the jack route mount those in front of the front tire not behind the tire, Big Foot mount theirs behind the front wheel and are not real stable IMO

[sparkplug188]

The nice thing about air bags is, it is much easier to control "bleed down" in an air leveling system.  All that is needed is a control panel with four adjustable pressure regulators, four lowering valves, and four pressure gauges.  I might scrap the jacks idea in favor of air bags, just for the future-proofing and proven working design.

Check the edits on my previous post.

Edit: On second thought... I should wait to see how Eagle plumbed them on the schematic.  The unloading of the suspension on bumps would cause the pressure regulators to continually overfill the air bags.

[bs4104]

Question:   Are you going to used oil in the air line tubing??
Bruce